# Acacia-Commiphora total AGB, M8 (rho D2 H, crown width, D30) Aboveground biomass equation for Eleven woody species of the Acacia-Commiphora biome (mixed), Ethiopia, from Amanuel et al. 2024. 140 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it. ## Equation As printed in Amanuel et al. 2024 (Table 3, AGBTotal rows, p. 6; model form in Table 1, p. 4): > 8a –0.6207 0.2108 0.4041 0.0911 0.4999 0.2052 0.4446 0.2240 0.40b 0.83b 0.83b Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#equation In this library's units, ready to compute (aboveground biomass in kg): ``` Aboveground biomass = exp(-0.6207 + 0.4041 * ln(rho * D^2 * H) + 0.4999 * ln(CD) + 0.4446 * ln(D30)) ``` Inputs: rho = Wood density (oven-dry mass / green volume) (g/cm³); D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m); CD = Crown diameter (m); D30 = Stem diameter at 30 cm (cm). The source's own form: exp(-0.6207 + 0.4041 * ln(rho * D^2 * H) + 0.4999 * ln(CW) + 0.4446 * ln(DSH30)), with CW in m, D in cm, DSH30 in cm, H in m, rho in g/cm3; output in kg. Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#canonical ## What it covers - Output: Aboveground biomass, kg - Taxon: Eleven woody species of the Acacia-Commiphora biome (mixed) (mixed species); broadleaf - Where: Bena-Tsemay district, southern Ethiopia. Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#where - Biomes: tropical, dryland - Stand: natural - Trees measured: 140. Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#n_trees - R²: 0.83. Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#r2 - Method: ln-ln multiple linear regression (SAS); no correction factor stated. Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#method - Verification: read in the original source - Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#checked_at A missing fit statistic is one the source doesn't state, or that we haven't recorded; it is never estimated. Outside the stated DBH range or region, the equation is an extrapolation. ## Source Amanuel, W., Tadesse, C., Molla, M., Getinet, D., Mekonnen, Z. (2024). Allometric equation for estimating aboveground biomass of Acacia-Commiphora forest, southern Ethiopia. Journal of Ecology and Environment, 48, 20. - DOI: https://doi.org/10.5141/jee.24.036 - Access: open access - Copy we read: https://www.e-jecoenv.org/journal/download_pdf.php?doi=10.5141/jee.24.036 - Every equation from this source: https://treeallometry.org/sources/amanuel-2024/ - Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#source ## The facts, in the source's words **Equation** (Table 3, AGBTotal rows, p. 6; model form in Table 1, p. 4): > 8a –0.6207 0.2108 0.4041 0.0911 0.4999 0.2052 0.4446 0.2240 0.40b 0.83b 0.83b Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#equation **model form** (Table 1, p. 4): > AGBest. = exp {α + β1Ln (ρ.D2.H) + β2Ln (CW) + β3Ln (DSH30)} Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#quote-model-form **Trees measured** (Methods, Biomass measurement, p. 3): > The biomass of the 140 individual trees was considered for biomass model development. Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#quote-fit-n-trees **R²** (Table 3, AGBTotal, columns R2 / Adj-R2): > 8a –0.6207 0.2108 0.4041 0.0911 0.4999 0.2052 0.4446 0.2240 0.40b 0.83b 0.83b Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#quote-fit-r2 **Our note:** Total aboveground dry biomass (stem + branches + foliage summed). In the paper D is DBH (cm), DSH30 is stem diameter at 30 cm (mapped to D30), CW is crown width (mapped to CD, m), rho is basic wood density (g/cm3). R2 shown is the printed R2 (Adj-R2 is within 0.01). No back-transformation correction factor is printed, so none is applied. The paper prints the mean D (12.61 cm) and a D range width of 29 cm but no min or max, so no DBH range is stored. RMSE printed in Table 3 is on the log scale. n = 140 is the full sample; Methods (p. 3) say 30% was held out for validation, so the fitted n may be ~98. The abstract and Results text say DSH10; Table 1 and the printed equations use DSH30, used here. ## Checks this equation passes On every build, the library's form and the source's own form (in its units) must both give these values within 1%. | Inputs | Expected | We get | From | | --- | --- | --- | --- | | D = 8, H = 4, rho = 0.7, CD = 3, D30 = 9 | 20.1 | 20.1 | Computed from the printed form: computed from the published form (coefficients as printed, no correction factor) | | D = 15, H = 6, rho = 0.7, CD = 4.5, D30 = 16 | 62.3 | 62.3 | Computed from the printed form: computed from the published form (coefficients as printed, no correction factor) | | D = 25, H = 8, rho = 0.7, CD = 6, D30 = 26 | 152 | 152 | Computed from the printed form: computed from the published form (coefficients as printed, no correction factor) | Cite: https://treeallometry.org/equations/amanuel-2024-total-m8/#checks The calculator on the page shows carbon as biomass × 0.47 (IPCC 2006 Guidelines, Vol. 4, Ch. 4, Table 4.3) and CO₂e as carbon × 44/12. ## How to cite Cite the source for the equation: Amanuel, W., Tadesse, C., Molla, M., Getinet, D., Mekonnen, Z. (2024). Allometric equation for estimating aboveground biomass of Acacia-Commiphora forest, southern Ethiopia. Journal of Ecology and Environment, 48, 20. https://doi.org/10.5141/jee.24.036 Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Acacia-Commiphora total AGB, M8 (rho D2 H, crown width, D30)", checked 2026-11-02, https://treeallometry.org/equations/amanuel-2024-total-m8/. Data CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Quotes are the authors' words. Data for this equation: https://treeallometry.org/data/equations/amanuel-2024-total-m8.json Report a problem: email info@restorationscope.com with the equation id (amanuel-2024-total-m8) and where the right value appears.